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1.
中国农田的温室气体排放 总被引：70，自引：2，他引：70
李长生 肖向明 S.Frolking B·Moore Ⅲ W.Salas 邱建军 张宇 庄亚辉 王效科 戴昭华 刘纪远 秦小光 廖柏寒 R.Sass 《第四纪研究》2003,23(5):493-503
中国是一个农业大国,拥有约1.33百万平方公里的农田。这些田地的种植、翻耕、施肥、灌溉等管理措施不仅长期改变着农田生态系统中的化学元素循环,而且给全球气候变化带来影响。农业生态系统对全球变化的影响主要是通过改变3种温室气体,即二氧化碳(CO2)、甲烷(CH4)和氧化亚氮(N2O)在土壤-大气界面的交换而实现的。为了分析多种因素(如气候、土壤质地、农作物品种及各种农田经营管理措施等)对农业土壤释放CO22222222 相似文献
2.
Doklady Earth Sciences - Carbon calculators are programs for calculating greenhouse gas emissions (a carbon footprint) from agricultural production on the farm scale. They are created on the base... 相似文献
3.
农业温室气体清单方法研究最新进展 总被引：14，自引：0，他引：14
为了履行气候变化框架公约的义务,缔约国要按时编制并提交国家温室气体清单。文章主要介绍温室气体清单指南中土壤CO2的排放和清除,稻田甲烷的排放,农业土壤中氧化亚氮的直接排放和间接排放等方面温室气体估算方法的研究进展。《2006年IPCC指南》中强调国家清单只报告管理土地CO2的排放和清除;采用六类土地利用类型体制,即：林地、农地、草地、湿地、居住地和其它地;提供了多层次的估算方法;稻田甲烷的季节排放因子变为日排放因子;农业土壤氧化亚氮的排放因子进一步修正;生物氮的固定不再作为氧化亚氮直接排放的排放源。清单方法改进的同时,我国编制农业温室气体清单面临巨大困难与挑战。 相似文献
4.
根据《中华人民共和国气候变化初始国家信息通报》,1994年中国温室气体排放总量约为3650×106t的CO2当量,其中CO2,CH4和N2O分别占73.1 ％ ,19.7 ％ 和7.2 ％ 。CO2排放主要来自能源活动,CH4排放主要来自农业活动和能源活动,N2O排放主要来自农业活动。在过去的20余年里,中国为减缓全球温室气体排放的增长速度做出了重要的贡献。对文献资料和大量研究结果的分析表明,中国可通过采取相关措施和制订相应政策进一步减少温室气体的排放。减少CO2排放的主要措施和对策包括:调整能源结构(降低煤炭消费比例、适度提高天然气比例和发展核能);提高能源生产、转化、分配和使用过程中的效率;开发利用水能、风能、太阳能和生物能等可再生能源;通过植树造林,推广秸秆还田、平衡施肥和少(免)耕等增加陆地生态系统的碳吸收。减少CH4排放的主要措施和对策包括:回收利用煤层气;改造生活垃圾填埋场地和筛选环境适应性强的CH4氧化菌并接种于填埋场;改善反刍动物的营养成分;稻田合理灌溉、提高水稻的收获指数、选育和种植CH4排放低的水稻品种等。减少农田N2O排放的主要措施和对策包括:提高氮肥利用率;推广施用长效肥和控释肥;施用生物抑制剂和实施微生物工程等。 相似文献
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6.
Life cycle analysis (LCA) methodology was used to perform a quantitative, comparative analysis and rating of the construction and operation of a wind energy plant. For this case study, the Glacier Hills Wind Park (90 1.8-MW turbines in south-central Wisconsin) was evaluated. Significant environmental and economic benefits are often advertised with the installation of new wind energy facilities, although independent and comprehensive LCA and sustainable energy science are typically not implemented. Hence, a quantitative demonstration with LCA methodology of the life cycle emissions and environmental impact, from construction through operations, can greatly assist in highlighting significant areas of energy consumption and emissions during manufacturing, transportation, and construction of a wind farm. Results portray the amount of greenhouse gas emissions and energy consumption/generation over the life cycle of the wind park. Transportation of large components from overseas led to the consumption of considerable quantities of fossil fuel, responsible for up to 22 % of the total greenhouse gas emissions due to transportation. The energy payback ratio (25.5), energy payback time (12.3 months) and the total grams of equivalent CO2(eq) per kWh of energy (16.9) produced were calculated over the life time of this onshore wind farm. 相似文献
7.
H. Najafi Alamdarlo 《International Journal of Environmental Science and Technology》2016,13(8):2079-2090
Agriculture and natural resources have a mutual relationship with each other. The purpose of this study was to evaluate forward and backward relationship between natural resources and agricultural development. The relationship between the consumption of water and agricultural value added per capita income has been studied in order to obtain the forward relationship, and the relationship between carbon dioxide emissions and per capita income of the Iran’s agricultural sector has been assessed in order to obtain backward relationship. To test these relationships, the Kuznets theory is used. Therefore, Iran’s provinces information from 2001 to 2013 was used and models were estimated by using the panel data and spatial econometric. Results showed that there was an inverted U relationship between per capita income and water consumption and carbon dioxide emissions. Also, spatial estimation showed that both water consumption and carbon dioxide (CO2) emissions in agricultural sector had a direct relationship with the value of these two variables in the neighboring areas. 相似文献
8.
农田排水沟渠作为农业景观中重要的景观单元,能够调节农田生态系统水分平衡,改变流域水文情势。农田养分可以随排水过程迅速流失,也可以通过沉淀与吸附机制被农田沟渠所截留或者通过植物吸收后收割与反硝化去除等机制脱离农田生态系统。作为农田生态系统边缘的交错带,农田排水沟渠较高的植物多样性可以提供动物栖息地和避难场所,增加农田生态系统生物多样性。清淤、收割和控制排水等管理措施对于农田排水沟渠的环境效应和生态服务功能有着不同的影响。今后应加强从多个学科研究农田排水沟渠的环境效应和生态功能,探索生态排水沟渠的构建和管理技术,实现农田排水沟渠水利功能和生态功能的"双赢"。 相似文献
9.
Robert Ugochukwu Onyeneke Christiana Ogonna Igberi Christian O. Uwadoka Jonathan Ogbeni Aligbe 《GeoJournal》2018,83(2):333-346
This paper explored the status of climate-smart agriculture (CSA) in southeast Nigeria using qualitative and quantitative methods in data collection. One hundred and sixty farmers were selected from the area. Also, focus group discussions were conducted. Data collected were subjected to qualitative analysis and logit regression. The study identified five broad and important practices relevant to CSA in southeast Nigeria, which include: adjusting agricultural production systems, mobility and social networks, farm financial management, diversification on and beyond the farm, and knowledge management and regulations. The determinants of CSA in southeast Nigeria include: education, income, credit, extension, livestock ownership, farming experience, land area cultivated, distance to the market and water resources, leadership position, risk orientation, gender, land ownership, household size, and mass media exposure. Government policies need to support research and development that develops and diffuses the climate-smart technologies to help farmers respond changes in climatic conditions. 相似文献
10.
Climate change adds another dimension of challenges to the growth and sustainability of Indian agriculture. The growing exposure to livelihood shocks from climate variability/change and limited resource base of the rural community to adapt has reinforced the need to mainstream climate adaptation planning into developmental landscape. However, a better understanding of micro-level perceptions is imperative for effective and informed planning at the macro-level. In this paper, the grass-root level perspectives on climate change impacts and adaptation decisions were elicited at farm level in the Moga district of Punjab and Mahbubnagar district of Telangana, India. The farmers opined that the climatic variability impacts more than the long-term climate change. They observed change in the quantum, onset and distribution of rainfall, rise in minimum as well as maximum temperature levels, decline in crop yield and ground water depletion. The key socio-economic effects of climate change included decline in farm income, farm unemployment, rural migration and increased indebtedness among farmers. In order to cope with climate variability and change thereon, farmers resorted to adaptation strategies such as use of crop varieties of suitable duration, water conservation techniques, crop insurance and participation in non-farm activities and employment guarantee schemes. Farmers’ adaptation to changing climate was constrained by several technological, socio-economic and institutional barriers. These include limited knowledge on the costs–benefits of adaptation, lack of access to and knowledge of adaptation technologies, lack of financial resources and limited information on weather. Besides, lack of access to input markets, inadequate farm labour and smaller farm size were the other constraints. Further, on the basis of the grass-root elicitation a ‘Need-Based Adaptation’ planning incorporating farmers’ perceptions on climate change impacts, constraints in the adoption of adaptation strategies and plausible adaptation options were linked with the most suitable ongoing programmatic interventions of the Government of India. The study concluded that micro-level needs and constraints for various adaptation strategies and interventions should be an integral part of the programme development, implementation and evaluation in the entire developmental paradigm. 相似文献
11.
The purpose of this paper is to expand debate about the future landscapes of the upper Midwest of the United States. The paper addresses options that could reinvent the agricultural systems of the Corn Belt, which coincides with the Upper Mississippi River Basin. The changes would move this region from one dependent on a grain economy, with low economic returns and high nutrient and sediment losses, to a more ecologically-based landscape emphasizing nutrient sinks, especially for nitrogen, and a legume base for supplementing fertilizer nitrogen. The reinvented systems require a higher level of management to lessen nitrogen and phosphorus losses while supporting family farms and strong rural communities. This reinvented agriculture would ultimately benefit the Gulf of Mexico by significantly lowering the amount of nitrate exported to the Gulf. The paper is not intended to be a comprehensive review of the literature, nor one that offers the full range of options to address the problems facing the watershed and the owners and operators of the land. Rather, I hope to facilitate discussion of the goals of midwestern U.S. agriculture in relation to ecosystem protection. 相似文献
12.
一种新型浅层井CO2监测系统的研发 总被引：2，自引：0，他引：2
碳捕集、利用与封存（CCUS）能够有效降低传统能源产业CO2排放量,缓解气候变化。地层中CO2泄漏,作为潜在风险之一,可能改变浅层地下水水质,影响地表动植物生长,甚至危及周围人群安全。为监测CO2是否泄漏至地表并评估泄漏对浅层地下水的影响,进行浅层地下水连续取样十分必要,为此开发了一种新型浅层井CO2监测系统。详细介绍了该系统的构成、工作原理、技术难点应对措施和操作步骤。该系统基于U形管原理：渗入井筒的地下水通过单向阀进入U形管内,而后采用氮气对U形管的一端加压,U形管的另一端得到样品。该系统能连续对地下不同层位（层位数根据实际需求确定）进行取样,为封存现场环境风险预警系统提供组成数据。 相似文献
13.
The world has been undergoing a remarkable process of urbanization, especially in developing countries in recent years. The urbanization process has brought about great urban development and large population agglomeration, changes in production and lifestyle, and man-made disturbances such as greenhouse gas and pollution emissions. As the global urbanization process continues to advance, its impact on climate change continues to strengthen significantly. This paper mainly reviewed and summarized relevant researches from two aspects: the influence of urbanization on climate change and the mechanism of influence of urbanization on climate change. Urbanization causes regional warming and urban heat island effect, extreme events such as high temperature, heat wave and heavy rainfall increase in frequency, and also leads to increased urban flood risk. The increase of pollutant emission in the process of urbanization is the main cause of air quality deterioration. Urbanization also has an indirect impact on air quality by changing urban climate. Urbanization has an important impact on climatic factors such as relative humidity, wind speed, sunshine and cloud cover. The impacts of urbanization on climate change are mainly realized through underlying surface changes, greenhouse gas and pollution emissions, anthropogenic heat emissions and urban high heat capacity. Urbanization not only directly affects the regional/local climate, but also indirectly affects the regional/local climate by promoting global climate change. Therefore, the impact of urbanization on climate change has a global and regional multi-scale superposition effect. 相似文献
14.
《Geoforum》2015
Private sector actors are playing an increasingly significant role in the definition and governance of ‘sustainable’ agri-food practices. Yet, to date little attention has been paid by social scientists to how greenhouse gas (GHG) emissions are addressed as part of private agri-food governance arrangements. This paper examines how private actors within agri-food supply chains respond to emerging pressure for measures to reduce GHG emissions from agriculture. Drawing upon the Anglo-Foucauldian governmentality literature, we introduce the notion of the corporate carbon economy to conceptualise the practical techniques that enable private agri-food actors to make GHG emissions thinkable and governable in the context of existing market, regulatory, and supply chain pressures. Using a case study of the Australian dairy industry, we argue that private agri-food actors utilise a range of techniques that enable them to respond to existing government environmental regulations, balance current market pressures with future supply chain requirements, and demonstrate improved eco-efficiency along food supply chains. These techniques – which include environmental self-assessment instruments, tools for measuring GHG emissions, and sustainability reporting – have little direct relevance to the ‘international climate regime’ of carbon trading, and carbon markets more broadly, yet individually and in combination they are crucial in enacting an alternative regime of GHG governance. In concluding, we contend that the growing use of sustainability metrics by international food companies is likely to have the most powerful implications for GHG governance in the agri-food sector, with potentially far-reaching consequences for how future action on climate change is rendered thinkable and practicable. 相似文献
15.
Malki Mouna Choukr-Allah Redouane Bouchaou Lhoussaine Ait Brahim Yassine Hirich Abdelaziz Barbara Reichert 《Arabian Journal of Geosciences》2016,9(10):566
The Chtouka-Massa area in Southern Morocco has shown an increase in water scarcity during the last decades, caused mainly by withdrawal of water resources aggravated by agricultural intensification and climate change impacts. To better understand the changes of groundwater quality, a sampling campaign was conducted in many wells during March 2015 and compared to historical chemical data from the hydraulic basin agency, as well as previous studies performed at Ibn Zohr University. All data were used to assess the spatial-temporal evolution of nitrate and salinity relevant to the recent sampling. This paper describes the current state of groundwater quality in the Chtouka-Massa zone with an overview of different sources of water mineralization and the nitrate evolution in an agricultural area. Our results indicate a general increase in mineralization from the north to the south, and from the east to the west. The plain, dominated by farms, shows a relatively high conductivity (up to 2000 μS/cm), while in both costal area and Anti-Atlas Mountain the water salinity shows a gradient increase from the north to the south. However, the highest electrical conductivity is observed along the Massa River. The water type is bicarbonate, chloride, and sodium for farm samples, while from the other parts, it is mostly dominated by chloride and sodium. The spatial-temporal analysis of nitrates generally shows an increasing trend. However, the levels remain overall lower than the limit. The temporal evolution of control points set by the hydraulic agency shows a decreasing trend decline that can be explained by the improvement of agriculture practices, including the conversion towards drip irrigation mode. Different chemical tracers highlighted some processes involving the changes of mineralization of groundwater (e.g., irrigation water return, marine intrusion, and water/rock interaction). The results will be used to improve water management in this area showing water quality degradation. 相似文献
16.
James B. Bell 《Geology Today》2014,30(5):192-195
Gas hydrates are the largest deposits of hydrocarbons in the world. They are distributed throughout marine sediments and their stability depends largely upon temperature and pressure. Typically, ～99 percent of these hydrocarbon deposits are composed of methane, which is a potent greenhouse gas. Methane release from gas hydrates has been implicated in mass extinction events. Present and future changes in ocean temperature have the potential to increase the rate of methane production from gas hydrates and thus to affect Earth's climate. Whilst the deep sea normally serves as a sink for greenhouse gases, the release of methane from gas hydrates could be a hugely significant source in the future and pose a real threat to our efforts to limit greenhouse gas emissions. 相似文献
17.
生物地球化学作为一个学科包含4个概念,即生物地球化学量、流、群和场.这4个概念从不同角度描述了生命与其环境的关系.生物地球化学量探索生命及其无机环境在元素丰度上的相似性,这种相似性决定了生命体对环境化学状态的依赖性.生物地球化学流描写化学元素在生态系统中的迁移,此迁移导致了生命体与环境间的物质和能量交换.生物地球化学群描述化学元素在迁移转化时的复杂组合关系及其生物效应.生物地球化学场是生态系统中控制生物地球化学反应的各种环境营力的总和.生物地球化学模型即是这一综合力场及其对化学元素迁移转化影响的数学描述,DNDC模型即基于这些概念发展起来.DNDC模型可用来预测陆地生态系统中碳和氮的生物地球化学行为,该模型已被一些国家用来预测农业土壤的长期肥力和温室气体排放. 相似文献
18.
In Europe the process of agricultural engagement or disengagement is attributed to the economic factor and mainly on the level
of alternative employment source development. It is the relational quality of economic, social and environmental factors that
determine sustainability of agricultural holdings and, hence, households. In regions of poor agricultural structures and of
many employment opportunities as well as in regions suffering from agricultural depression, households exhibit stronger tendencies
towards agricultural disengagement. Remarkably in southern Europe a stable agricultural engagement and not disengagement is
observed, even though in recent years there are limited possibilities of alternative income sources and prevailing agricultural
depression. This article highlights the factors which lead households to stable engagement with agriculture in a region of
southern Europe, the island of Lesvos. The island is characterised by traditional olive grove mono-culture, poor agricultural
structures and limited employment opportunities. The investigation of the economic, social and environmental farm household
characteristics concluded that in regions where poor agricultural infrastructure and lack of employment prevail, all three
factors of sustainability contribute to stability and/or low agricultural disengagement. Among these, the economic factor
is the most sensitive and hence highly influential. The social factor is highlighted as a quality and consistent factor due
to the respect for tradition. The environmental factor, finally, is characterised by mild cultivation practices, contributing
to environment conservation. 相似文献
19.
Atmospheric deposition of nitrogen: Implications for nutrient over-enrichment of coastal waters 总被引：8，自引：0，他引：8
Atmospheric deposition of nitrogen (AD-N) is a significant source of nitrogen enrichment to nitrogen (N)-limited estuarine and coastal waters downwind of anthropogenic emissions. Along the eastern U.S. coast and eastern Gulf of Mexico, AD-N currently accounts for 10% to over 40% of new N loading to estuaries. Extension of the regional acid deposition model (RADM) to coastal shelf waters indicates that 11, 5.6, and 5.6 kg N ha−1 may be deposited on the continental shelf areas of the northeastern U.S. coast, southeast U.S. coast, and eastern Gulf of Mexico, respectively. AD-N approximates or exceeds riverine N inputs in many coastal regions. From a spatial perspective, AD-N is a unique source of N enrichment to estuarine and coastal waters because, for a receiving water body, the airshed may exceed the watershed by 10–20 fold. AD-N may originate far outside of the currently managed watersheds. AD-N may increase in importance as a new N source by affecting waters downstream of the oligohaline and mesohaline estuarine nutrient filters where large amounts of terrestrially-supplied N are assimilated and denitrified. Regionally and globally, N deposition associated with urbanization (NOx, peroxyacetyl nitrate, or PAN) and agricultural expansion (NH4 + and possibly organic N) has increased in coastal airsheds. Recent growth and intensification of animal (poultry, swine, cattle) operations in the midwest and mid-Atlantic regions have led to increasing amounts of NH4 + emission and deposition, according to a three decadal analysis of the National Acid Deposition Program network. In western Europe, where livestock operations have dominated agricultural production for the better part of this century, NH4 + is the most abundant form of AD-N. AD-N deposition in the U.S. is still dominated by oxides of N (NOx) emitted from fossil fuel combustion; annual NH4 + deposition is increasing, and in some regions is approaching total NO3 − deposition. In receiving estuarine and coastal waters, phytoplankton community structural and functional changes, associated water quality, and trophic and biogeochemical alterations (i.e, algal blooms, hypoxia, food web, and fisheries habitat disruption) are frequent consequences of N-driven eutrophication. Increases in and changing proportions of various new N sources regulate phytoplankton competitive interactions, dominance, and successional patterns. These quantitative and qualitative aspects of AD-N and other atmospheric nutrient sources (e.g., iron) may promote biotic changes now apparent in estuarine and coastal waters, including the proliferation of harmful algal blooms, with cascading impacts on water quality and fisheries. 相似文献
20.
Part-time farming is a feature and a consequence of economic change which involves labour movement out of agriculture. It helps to sustain the rural sector by reducing the rate of outmigration. This paper reports on a pilot survey of part-time farmers in the S, Government-controlled part of Cyprus. The economy is growing rapidly with agriculture declining in relative importance although still contributing nearly half the value of exports. Over 50 % of farmers are part-time, meaning in this case they have another occupation. In general, farming is a minor activity and time spent in off-farm work is often increasing to maintain income levels. However the majority of the sample are keen to maintain their farming activity.In the Cyprus study part-time farmers appear slightly younger and operate smaller units than average; they rent in less land and irrigate a smaller area. Considerable differences are found between the four main agricultural zones; mountain, vines, dryland and coastal. At one extreme, exemplified by the coastal zone, commercial part-time farming provides a high standard of living on farms which are somewhat smaller than average. Off-farm work is available locally and complements farm work. Farmers' confidence in long-term prospects is reflected in their willingness (and ability) to invest on the farm and in their low levels of family, migration. At the other extreme, found in the depressed areas of the mountain zone, overt government policies may be required to ensure the continued existence of farming. The combined income of on and off farm work may be inadequate and farmers often have to borrow to meet basic household needs. These farmers travel long distances to find work and may have more than one off-farm occupation. Much of the burden of farm work falls on other family members. Although farmers would prefer to spend more time in agriculture they have limited confidence in its future prospects and recognize the possible necessity of outmigration. 相似文献